Drill stem test packer



Dec. 2, 1958 J. H. HUGHES DRILL STEM TEST PACKER Filed Feb. 15, 1957 INVENTOR. J. H. HUGHES A f TORNE r5 United States Patent DRILL STEM TEST PACKER James H. Hughes, Alexandria, Va., assignor to Phillips Petroleum Company, a corporation of Delaware Application February 15, 1957, Serial No. 640,453

6 Claims. (Cl. 166-187) V This invention relates to a drill stem test packer for a well bore which is insertable in the lower end of the drill string and which can be actuated without pulling the pipe from the well.

When drilling oil wells, it is often desirable to test formations being drilled. The usual procedure is to remove the drill string from the well, run a complicated testing tool comprising a packer and a system of valves which makes it possible to run the pipe empty, seat the packer and then open the pipe to the formation to be tested. Since the pipe does not contain heavy drilling fluid, the pressure prise lowering a sample container and involve a' rather complicated apparatus.

is removed from the formation being 7 tested, thus permitting the formation fluids to flow into Accordingly, it is an object of the invention to provide a device comprising a packer for effecting drill stem testing without removal of the drill string from the well bore. It is also an object of the invention to provide an aparatus useful in drill stem testing which materially reduces the time of the operation. Other objects will become apparent from a conslderation of the accompanying disclosure. I have devised an apparatus for insertion in a drill string near the lower end thereof or adjacent the drill bit, which includes a flexible, inflatable packer, means for inflating or setting the packer against the wall of the hole or against a casing therein, means for cutting off flow of fluid through the drill string below the packer, means for passing drilling fluid through the wall of the drill string just above the packer ward flow into the drill string so as to reducethe 'pres sure in the drill string and permit flow of formation fluid into the same, and means for releasing the packer and opening up the drill bit while cutting off flow into the annulus through the wall of the drill string above the bit.

The drill stem test packer of the invention is particularly adapted to operate in the process disclosed in the copending application of Robert S. Hoch, Serial No. 607,025, filed August 30, 1956. is disclosed a method for displacing the drilling liquid or mud from the drill string in a well to the depth of the formation being tested regardless of the depth of the formation utilizing a compressor such as one which de velops 1500 p. s. i. at the outlet of the compressor. method comprises displacing the non-compressible drilling liquid or mud inside the drill pipe with a regulated mixture of air and mud (aerated drilling mud) by forcing the mixture into the drilling string so as to force the regular drilling liquid down the drill string and into the annulus surrounding same from which the mud flows out the well head into the mud pit. An alternative method comprises introducing alternate slugs of air' and mud so that the air-mud sequence progressively displaces the continuous column of mud inside the drill string.

while preventing back- I drill string to flow of fluid to the In said application there The N1 2,862,562 l atented Dec. 2 1958 "ice j The discharge pressure of the air compressor and the mud pump steadily increases up, to the pressure rating of the air compressor when operating in deep wells and it isthen necessary to cut ofi the supply of air and use the mud pump only; The introduction of a slug of mud reduces the surface pressure in proportion to the length of the slug of mud and permits the injection of more air. Aerated mud injection can then be resumed until the pressure reaches the pressure capacity of the compressor at which time the compressor is again shut off and continuous phase mud is injected to again reduce the surface pressure. This on-again-off-again technique is continued until the air-mud mixture reaches the depth at which fluid evacuation is assured.

In the procedure described the mud passes from the drill string to the annulus thru a control valve. which either closes automatically to the back flow of mud or can be operated so as to prevent the return flow of mud into the drill string from the annulus. The next step in the process comprises closing the valve between the annulus and hollow drill string. The annulus is packed 01f below the valve in the drill string so. that mud cannot flow thru the annulus below the packer. In other words, the annulus is packed off above the formation to he tested. and below the conduit or valveleading from the drill string to'the annulus. The third step comprises opening the upper end of the drill string to vent the fluid therein which, because of the highly compressed nature of the air-mud mixture, quickly expands and flows back to the surface reserve mud pit. The highly compressed air in the drill string produces adequate energy to dis-place most of the fluid fromthe drill string and any fluid pressure from the formation being tested causes the formation fluid to rapidly rise thru the drill string.

The method described in the Hoch application is adaptable to testing while drilling without removing the pipe and bit from the well but requires a suitable packer 'and valve apparatus. The present invention comprises such a packer andvalve apparatus. A more complete understanding of the inventionmay be 'had by reference to the schematic drawing which is a longitudinal partial cross section of a drill stem test "packer in accordance with the invention.

Referring to the drawing, the apparatus the body 41, a valve sleeve 42, inner sleeve 43, flexible, inflatablev packer element 44, and springs 45 and Y46. Spring 46 is of considerably greater compression strength than spring 45. The body 41 is provided with threaded ends 47 and 48-for attachment within the drill string. Inner bore 49 narrows at shoulder 50 and the fluid passageway continues through port 51. Ports 52,53, and 54'in body 41 are provided with check valves 56, 57, and 58 respectively, the flow thru the valves being in the direction of the arrows. A reduced diameter section 59 of body 41 provides space for the packer element 44 which is held in place by clamping rings,61 and 62. An annular depression 60 is cut in the inner bore .49 as shown. Packer element 44 may be made of any suitable packer material such as oil resistantjrubberq Valve sleeve 42 is provided with seal rings 63, 64, 65, 66, and 67 and with ports 68 and 69. A plurality' of hinged dogs 71, attached to an upperend section of valve sleeve 42, are spring biased to forcetheupper ends radially outwardly. A shoulder 72 supports spring 45. Inner sleeve 43 is provided with avalve. seat 73 which may be threaded into the sleeve or integral therewith, a plurality of slots 74 and an upper sealing portion 75, which can be provided with seal rings, if desired. Slots 74 may be replaced by other types of perforations. A ring 76, attached in the upper; portion of valve sleeve 40 comprises 3 42, restricts upward movement of inner sleeve 43. An actuating member 77, which is not in place in normal drilling operations, is lowered on cable or wire line 78 when it is desired to'actuate the apparatus.

In operation, while the well .is being drilled, circulation-of drilling fluid is thru bore 49, the inner portion of valve sleeve 42 and inner sleeve 43, past valve seat -73, thru port 51 and. downward thru any drill collars located below the packer, and then thru the bit. Port 52 is sealed between seal rings and 65, and port 53 is sealed between seal rings 66 and 67. Port 54 is uncovered but is.closed by check valve 58.

When a test is to be made, actuating member 77 is lower ed on line 78 until it seats on valve seat 73. Fluid pressure is then applied within the drill string, thus moving inner sleeve 43 downward againstthe force of spring 45, causing sealing portion 75 to close ports 68. Further application of pressure results in downward movement of the entire inner assembly including valve sleeve 42. The first result of the downward movement is the closure of ports 54 between seal rings 66 and 67, followed immediately by the opening of ports 53 to ports 69. The fluid under pressure thus enters the space between packer element 44 andbody 41 thru valves 57 and expands the element 44 into contact with the well bore or casing.

When element 44 is expanded tightly against the well bore, -further application of pressure moves the assemblystill farther downward, again sealing off ports 53 between seal rings 64 and 65, and aligning ports 68 with ports 52. It will be noted that ports 54 still are closed between seal rings 66 and 67 and port 63 is closed by sealing portion 75. When hinged dogs 71 are opposite annular groove 60, they spring outward thus preventing upward movement of sleeve 42. The pressure then is reduced and actuating member 77 is raised a short distance, as shown, so that it is between valve seat 73 and dogs 7 1. This allows inner sleeve 43 to be raised by spring 45 thus uncovering port 68 and permitting circulation thru ports 52. Thecolumn can then be aerated as described in the above-identified Hoch application, followed by the drill stem test.

When the test has been completed, actuating member 77 is raised from the well bore. As it passes dogs 71, it. contacts their inner ends thus forcing them to be rotated; in a direction to disengage their upper ends from groove 60 This permits spring 46 to restore the apparatus to the position illustrated, thus uncovering ports 54,. allowing the fluid under pressure expanded element 44 to be discharged,and allowing the element to return to the position illustrated. I I Although actuating member 77 is relatively heavy it may, ifgthe flow through the toolis excessive, be forced upward, thus releasing dogs 71 allowing the packer to be released. Normally this can be prevented by controlling the rate of flow by means, such as a choke, at the surface. If desired, however, flow actuated means can be provided to prevent upward movement of member 77. For example, one or more perforated flappers can be provided, hinged to the inner wall of inner sleeve 43. The weight of such flappers will cause them to fall to a retracted position, allowing free movement of member 77 either up or down. Under a condition of excessive flow, however,- such flapper would be moved upward much in the manner as the flapper of a check valve, thus obstructing the passageway sufficiently to prevent upward movement of member 77 The device of the invention is applicable to drill string testing during drilling operations. The present method of drill stern testing, is a time-consuming and costly process because, prior to testing the formation, the drill string must be removed from the hole in order to place the testing packer at the bottom of the drill string and, also, for the purpose of floating the pipe into the hole. This floating in procedure is necessary to insure a pressure diflerential in the well bore after the packer is 4 set and the tool is opened. The method of the invention permits the testing of the formation for formation fluid without removing the drill stem by running of the described packer above the bit so that when an oil show or zone is encountered, the packer may be hydraulically or mechanically expanded above the prospective zone so as to seal off the annulus so that the drill stem evacuation and testing in accordance with the invention may be applied without tripping the drill string. This technique depends upon the use of a formation packer which can be run with the drill string and operated without removing the drill string from the hole.

It will thus be seen that the device of the invention provides a solid connection between the upper portion of the drill string and the drill bit but permits the seating and unseating of a packer when desired and communication between the inner and outer portions to be established, thus permitting the well test to, be made.

Utilizing the technique described, deep wildcat wells can be drilled to total depth before initiating the drill stern testing program. After total depth is reached, a straddle type packer or a single packer and bottom plug arrangement are used to progressively test each prospective zone starting with the lower zone. Present testing methods require trippingof drill pipe between each formation test and the method of 'this invention eliminates this time consuming phase of present day testing operations. I

Certain modifications of the invention will become apparent to those skilled in the art and the illustrative details disclosed are not to be construed as imposing unnecessary limitations on the invention.

I claim: I

1. A drill stem test packer comprising in combination an upright elongated cylindrical body member having an axial passageway and means at each end for attaching same in a drill string; a flexible inflatable annular packer of a diameter no larger than said member recessed in the outer surface of said member; means in an intermediate section of said passageway for cutting off longitudinal flow of fluid thru said body member; means for in-, troducing fluid thru said member behind said packer to inflate same; means for circulating fluid from said passageway laterally thru the wall of said member above said packer; valve means for preventing flow back into said passageway thru said circulating means; valve means for deflating said packer; and means for restoring flow thru said passageway and cutting off circulation thru the wall'of said member.

2. A drill stem test packer comprising in combination an upright elongated cylindrical body member having an axial; passageway and means at each end for attaching same in a drill string; a flexible inflatable annular packer recessed in the outer surface of said member; a valve sleeve slidably engaging the inner wall of said member having a circulating port thru an upper section and an inflating port thru a lower section; a circulating pert thru the wall of said member above'said packer having a check valve therein preventing flow inwardly; an inflating port thru said member to the area behind an upper section of said p'ac'ker having a check valve therein preventing inward flow; a deflating port thru said member to the area behind said packer below said inflating port having a check valve therein preventing outward flow; an inner sleeve slidably engaging the inner wall of said valve sleeve having an imperforateupper. section just above the circulating port in said valve sleeve and a slotted section therebelow communicating with each of the ports in said valve sleeve; a transverse valve seat in the lower end oftsaid inner sleeve; a first compression spring in the lower end of saidvalve sleeve supporting said inner sleeve and a second stronger and longer compression spring supporting said valve sleeve from a shoulder in a lower section of said passageway, said first spring being compressed by closing said passageway by an actuating meme her on said valve seat and applying fluid pressure within said passageway so as to lower said inner sleeve and cover said circulating port in said valve sleeve, and said second spring being compressed by an increase in said fluid pressure so as to bring said circulating ports into alignment for circulation of fluid from said passageway; means for locking said valve sleeve in circulating position; and means for releasing said valve sleeve.

3. The device of claim 2 wherein said locking and releasing means comprises an annular recess in the inner wall of said member; oblique dogs pivoted in an 'upper section of said valve sleeve with their upper ends slidably engaging the wall of said member, being outwardly urged so as to enter the hereinafter defined annulus upon arriving at same; an actuating member adapted to be lowered on a line into said passageway and to fit said seat and close same, said actuating member being small enough to clear said dogs before same are entered in said annulus and large enough to contact and release same when engaged; an annulus in the inner wall of said body member positioned so that said dogs engage same when said circulating ports in said valve sleeve and in said body member are aligned.

4. A drill stem test packer comprising in combination an upright elongated body member having an axial passageway and means at each end for attaching same to members of a drill string; a flexible inflatable packer recessed in an intermediate section of the outer wall of said body member; at least one inflating port thru the wall of said member behind said packer; at least one deflating port in the wall of said body member behind said packer positioned at a lower level than said inflating port; at least one circulating port thru the wall of said member above said packer having a check valve therein to prevent flow into said passageway from outside said member; an elongated valve sleeve slidably engaging the wall of said passageway adapted to cover aforesaid ports; an inner sleeve slidably engaging the inner wall of said valve sleeve; at least one circulating port in an upper section of said valve sleeve; at least one inflating port in a lower section of said valve sleeve; longitudinal slots in said inner sleeve opposite the ports in said valve sleeve; an inwardly extending shoulder in a lower section of said valve sleeve; a transverse valve seat in the lower end of said inner sleeve; a compression spring between said shoulder and the lower end of said inner sleeve supporting same within said valve sleeve; an inwardly extending shoulder in a lower section of said passageway; an elongated compression spring between l'ast said shoulder and the lowerend of said valve sleeve; and means for locking said valve in position in said passageway when the circulating ports in said valve sleeve and in said body member are aligned.

5. The device of claim 1 wherein means for inflating and deflating said packer comprises a first conduit leading from said passageway thru said member intermediate the ends of said packer, a sleeve member slidably engaging the wall of said passageway having a first port therein alignable with said first conduit, a second conduit leading from the area back of said packer thru said member into said passageway at a level below first said conduit, said first port in said sleeve being alignable with said second conduit upon lowering of said sleeve, and sealing means between said sleeve and said member above and below said first port; and wherein means for circulating fluid from said passageway laterally thru the wall of said member comprises a circulating conduit thru said wall above said packer, a second port in said sleeve above said first port alignable with said circulating conduit when said first port is intermediate said first and second conduits, sealing means between said sleeve and said member above and below said second port, and means for covering said second port when said first port is aligned with said first conduit.

6. The device of claim 5 wherein said sleeve is spring biased to position said secondport above said circulating conduit, said means for covering said second port comprises a slotted sleeve having an imperforate top section and spring biased with a weaker spn'ng than aforesaid spring to position said imperforate section just above said second port; and including unlockable means for locking said sleeve in circulating position.

References Cited in the file of this patent UNITED STATES PATENTS 

